What would NOT be true of an engine with a clogged converter?

An engine with a clogged converter typically exhibits several distinct symptoms, and understanding the behavior of exhaust gases is key to identifying these issues. A clogged catalytic converter generally leads to low exhaust flow, which can result in increased exhaust backpressure. This condition can cause low manifold vacuum at idle and may contribute to engine misfires, as the engine struggles to expel exhaust gases efficiently.

High oxygen content in the exhaust would not be true in this scenario. A clogged converter restricts the flow of exhaust gases, leading to incomplete combustion and resulting in higher levels of unburned hydrocarbons and carbon monoxide, rather than an increase in oxygen. If the converter is blocked, the exhaust will be rich in these compounds due to insufficient oxygen being present to facilitate complete combustion. This contrasts with a healthy exhaust system that allows for proper airflow and efficient combustion, which produces a more balanced mixture of gases, including oxygen. Thus, the presence of high oxygen content alongside a clogged converter does not align with typical engine behavior.